Marine Weather and Tide Forecast for Mattapoisett Center, MA

NEAR TERM /UNTIL 6 PM THIS EVENING/
Key Messages:

* Clouds lower and thicken from W to E as a weak disturbance approaches from the west.

Today:

A weak mid-level shortwave will be responsible for yet another unsettled Saturday in southern New England. Showers have already spread across MA, mainly northern MA so far. This isn't a strongly forced system, so despite having sufficient moisture there isn't enough lift/instability to support heavy rainfall.
Expect periods of showers to continue through the morning, filling in further south as the early morning progresses. The general trend shown by the suite of high-res guidance is the bulk of showers shifting south further into RI and SE MA early afternoon as a surface high nudges in. This should help initiate a gradual drying trend. Amounts will likely range in the 0.15-0.40" range. Temperatures will be below normal for this time of year with highs in the low to mid 60s. Offshore flow will keep it in the low 60s in the coastal areas.

SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/
Key Messages:

* Few showers possible early evening across the south coast, otherwise dry overnight.

Tonight and Sunday:

Surface high pressure remains offshore overnight keeping conditions dry overnight with light NE winds. Temperatures drop into the low to mid 50s.

Dry conditions are expected Sunday while still under the influence of the surface high. It will be another cool day with cool temperatures aloft and mainly cloudy skies. A weak wave moves across Sunday night. Battling the drier air shower chances will be low as well as coverage of showers.

LONG TERM /MONDAY THROUGH FRIDAY/
Key Points

* Warming trend Mon - Wed

* Hot and humid Thursday with potential for Thunderstorms

Surface flow turns more southerly on Monday in response to high pressure moving further offshore and developing low south of Long Island. This low should be far enough south to keep the region dry, but perhaps a few showers could reach the south coast. Temperatures begin to rebound, reaching the low to mid-70s. Temperatures are expected to continue warming on Tuesday and Wednesday, with highs in the mid-70s to low 80s. Precipitation chances are uncertain by midweek as some global models attempt to develop another weak surface low near Long Island. This system lacks strong upper-level support, so the most likely scenario is a few diurnal showers rather than a washout. Guidance comes back into better agreement towards the end of the week as a stronger shortwave exits the Great Lakes.
This could become the focus for more widespread showers and thunderstorms. The GFS and EURO indicate that upwards of 1000-2000 J/kg of instability is available on Thursday afternoon, which could lead to severe thunderstorms, depending on the timing of the leading cold front. With continued strong southerly flow, temperatures could warm to near 90°F by Thursday, with dewpoints in the mid-60s.
Temperatures cool a bit behind the cold front on Friday, dropping back down to the low 80s with Dewpoints in the upper 50s.

Looking way ahead to next weekend, there appears to be some hope that we will finally break out of the wet weekend trend as the GFS has a dry airmass following behind the shortwave from Thursday/Friday. However, the Euro and Canadian have another trailing shortwave, which would lead to another wet weekend.

AVIATION /09Z SATURDAY THROUGH WEDNESDAY/
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

06z TAF Update:

Through tonight...High confidence.

VFR, but lowering cigs tonight with areas of MVFR and scattered showers developing mainly after 06z from SW to NE.

Saturday...Moderate confidence.

MVFR/IFR with light rain showers in the morning, drying up in the afternoon with the exception of the Cape and Islands where rain will last into the afternoon

Saturday night...Moderate Confidence

MVFR/VFR. light NE winds.

KBOS Terminal...High confidence in TAF.

Off and on showers through about 11z this morning, then more steady light rain expected after 11z. CIGS should stay MVFR despite the onshore flow as high pressure to the north brings in drier air.

KBDL Terminal...High confidence in TAF.

Off and on showers mainly between 10-14z, although could linger through 17z. CIGS should remain MVFR with periods of IFR possible

Outlook /Monday through Wednesday/...

Monday: VFR.

Monday Night through Tuesday: Mainly VFR, with local IFR possible.

Tuesday Night: Mainly VFR, with local IFR possible. Slight chance SHRA.

Wednesday: Mainly VFR, with local MVFR possible. Slight chance SHRA, isolated TSRA.

MARINE
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

Today through Saturday...

E-NE winds speeds below 25 kt and most of the day today with seas less than 5 ft. Periods of showers expected today over south coastal waters. There may be a period after 20Z today where conditions across the southern outer waters approach SCA criteria with winds around 25 kts and brief 3-5 ft seas. This potential will last through 06Z. Seas and winds trend downward into early Sunday morning.

Outlook /Monday through Wednesday/...

Monday: Winds less than 25 kt. Seas locally approaching 5 ft.

Monday Night through Wednesday: Winds less than 25 kt.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 6 PM this evening to 2 AM EDT Sunday for ANZ256.